System for comminuting and straining sewage and the like



A. JELLESMA SYSTEM FOR COMMINUTING AND STRAINING SEWAGE AND THE LIKE Filed Sept. '7, 1962 3,247,970 SYSTEM FOR COMMINUTING AND STRAINING SEWAGE AND THE LIKE Anne Jellesma, Sneak, Netherlands, assiguor to W. Hubert & Co., Machinetabriek N.V., Sneek, Netherlands, a Dutch liability company Filed Sept. 7, 1962, Ser. No. 222,085 Claims priority, application Netherlands, Sept. 8, 1961, 269,056 3 Claims. (Cl. 210-174) The present invention relates to systems for handling sewage.

It is an object of the invention to provide a screen and a screw mounted within said screen, said screw having a rotating motion about its own axis and including a plurality of peripheral cutters, each of which is accommodated in circumferential slots in said screen. At least one slotted member is disposed outside said screen having openings in registry with said slots, the arrangement being such that upon rotation of said screw solid material which lodges in the slots of the screen is carried by said cutters to the slotted member and is comminuted between said cutters and the member.

It is another object of the invention to provide a comminutor as specified which is relatively simple in construction, occupies a relatively small place when mounted in a gully system, has only one rotating member, and is less expensive than the known structures of this kind.

A further object of the invention is to provide a comminutor in which the sewage effluent together with the crushed solids of the sewage within the screen are continuously stirred by the rotation of the screw inside the screen.

With these and other objects in view, as may appear from the accompanying specification, the invention consists of various features of construction and combination of parts, which will be first described in connection with the accompanying drawing, showing a comminutor of a preferred form embodying the invention.

In the drawing:

FIG. 1 is a side elevational view in cross-section of an embodiment according to the invention; and

FIG. 2 is a perspective view on enlarged scale of a detail portion of the embodiment of FIG. 1.

In the drawing there is shown an improved comminutor device disposed in a sink hole 3 of a gully system communicating with two drains 1 and 2. The-comminutor device includes a stationary cylindrical catch drum or screen 4 having a plurality of circumferentially extending slots 5. The solids of the sewage waste which are distributed in the waste water streaming through the screen 4 are intercepted by the screen and entrapped in the slots 5 of the screen 4. Combs or slotted members 6 are secured to the outer surface of the catch screen 4. One or more members 6 may be provided. The device illustrated in the drawing has two such members 6.

Each of these members 6 is stationary and each has a plurality of recesses or slots 7 in which counter-cutters (not shown) are received. The slots 7 of each member 6 are located in that edge of the member 6 which is adjacent the screen 4 and each slot 7 of the members 6 registers with one of the slots 5 of the catch screen 4. A conveying screw 9 is disposed within the catch screen 4 and is mounted on a shaft 8 arranged co-axially with the screen 4. The lower end of the shaft 8 is mounted in a bearing 10 fixed to a lower plate or end 11 of the catch screen 4. The plate 11, together with the bearing 10, is mounted on a lower wall 12 of the sink hole 3. The lower plate 11 and the bottom wall 12 have holes therethrough, these holes being so arranged that canals 13 are formed through which sewage eflluent separated United States Patent 0 3,247,970 Patented Apr. 26, 1966 'ice from the solids can flow from the inside of the catch screen 4 to an outlet drain 14. The upper end of the shaft 8 is mounted in a bearing 15, the bearings 10 and 15 maintaining the shaft 8 co-axial with the screen 4. The bearing 15 is secured to a brace member 16 which is supported by the top of the catch screen 4. The upper end of the shaft 8 extends beyond the bearing .15 and into a casing 17 in which reduction gearing (not shown) is arranged. This gearing is driven by an electric motor (not shown) disposed within a protective casing 18 provided with external cooling ribs. The casing 18, together with the electric motor, is supported by the casing 17 which in turn rests on the member 16 by way of a supporting plate 20 and columns 19.

Cutters 21 are secured, preferably by welding, to the edge of the conveying screw 9. Each of the cutters 21 registers with one of the slots 5 of the catch screen 4, the cutters 21 being distributed accordingly along the blade edge of the screw 9. The dimensions of the screw 9 and the length of the cutters 21 measured radially of the catch screen 4 are such that the screw can rotate freely inside the screen 4 and such that at the same time each cutter 21 extends through its corresponding slot 5 and beyond the outer surface of the screen 4. When the screw 9 is rotated the parts of the cutters 21 which extend beyond the outer surface of the screen 4 pass through the slots 7 in the members 6.

In use of the device, the shaft 8 and the screw 9 thereon are rotated by the electric motor. As the cutters 21 are carried around with the screw 9 they entrain the sewage waste caught in the slots 5 and carry this waste to one of the members 6. Thus as each cutter 21 passes through one of the slots 7 the cutter 21 co-operates with one of the counter-cutters to crush or comminute between them the solid material or particles carried by the cutter 21 to the member 6. In any case where the solids are not comminuted sutficiently when they first encounter one of the members 6, the material is carried around to the other .member 6 and further comminuting occurs. The comminuted waste is drained off by the sewage efiluent flowing" through theoutlet drain 1 It will be understood that the sewage eifiuent together with the crushed solids within the screen 4 is continuously stirred by the rotation of the conveying screw 9 inside the screen 4. This stirring prevents comminuted material settling within the apparatus and forming a cake of crushed material.

The direction in which the shaft 8 is rotated can be reversible and hence it is possible to change the direction in which the water moves inside the catch screen 4 from upwards to downwards or vice versa.

It will be understood that the invention is not to be limited to the specific construction or arrangement of parts shown, but that they be widely modified within the scope of the invention as defined by the claims.

What is claimed is:

1. In a sewage handling system the combination of a stationary hollow cylindrical drum, said drum having a plurality of spaced circumferential slots, at least one elongated comb member externally adjacent the drum and having a plurality of recesses in registry with the slots of the drum, a screw member constituting a conveyor coaxially supported within said drum for rotation, said screw member including a helical element having an outer periphery adjacent the slots in the drum, a plurality of cutters on the helical element at the periphery thereof extending through the slots of the drum and externally thereof such that upon rotation of the screw member the cutters traverse the slots of the drum and pass through said recesses in the member adjacent the drum, said screw member including a shaft supporting the helical element and projecting axially from the drum, and means engaging the projecting shaft for driving the shaft in rotation, said cutters being arranged on the outer periphery of the helical element to pass in succession into the recesses of the member adjacent the drum and comminute solid matter which is entrained in the slots and which is advanced by the cutters to said recesses such that fine comminuted particles will pass into the drum through the slots and be mixed therein with effluent which has passed through the slots and be conveyed by said screw member towards one of the ends of the drum.

2. The combination as claimed in claim 1 wherein the outer periphery of the helical element is arranged closely adjacent the drum to comminute between the periphery of the helical element and the drum, solids passing through said slots, whereby the screw member in addition to constituting a conveyor and a support for the cutters also serves to comminute solids.

3. The combination as claimed in claim 1 wherein said helical element includes. a hub and an integral spiral band, said hub being mounted on said shaft for rotation therewith.

References Cited by the Examiner UNITED STATES PATENTS 718,003 1/1903 Kemp 241-276 X 1,960,303 5/1934 Durdin 210174 2,195,815 4/1940 Hanna t 241--276 2,295,633 9/1942 Chase 210174 2,389,306 11/1945 Green 210-174 2,717,742 9/1955 Weighman et al. 241276 X 2,853,242 9/1958 Wiltsey 241-68 2,921,683 1/1960 Strenz et al. 210-174 3,091,338 5/1963 Nordel l 210-174 REUBEN FRIEDMAN, Primary Examiner.

HERBERT L. MARTIN, Examiner. 

1. IN A SEWAGE HANDLING SYSTEM THE COMBINATION OF A STATIONARY HOLLOW CYLINDRICAL DRUM, SAID DRUM HAVING A PLURALITY OF SPACED CIRCUMFERENTIAL SLOTS, AT LEAST ONE ELONGATED COMB MEMBER EXTERNALLY ADJACENT THE DRUM AND HAVING A PLURALITY OF RECESSES IN REGISTRY WITH THE SLOTS OF THE DRUM, A SCREW MEMBER CONSTITUTING A CONVEYOR COAXIALLY SUPPORTED WITHIN SAID DRUM FOR ROTATION, SAID SCREW MEMBER INCLUDING A HELICAL ELEMENT HAVING AN OUTER PERIPHERY ADJACENT THE SLOTS IN THE DRUM, A PLURALITY OF CUTTERS ON THE HELICAL ELEMENT AT THE PERIPHERY THEREOF EXTENDING THROUGH THE SLOTS OF THE DRUM AND EXTERNALLY THEREOF SUCH THAT UPON ROTATION OF THE SCREW MEMBER THE CUTTERS TRANVERSE THE SLOTS OF THE DRUM AND PASS THROUGH SAID RECESSES IN THE MEMBER ADJACENT THE DRUM, SAID SCREW MEMBER INCLUDING A SHAFT SUPPORTING THE HELICAL ELEMENT AND PROJECTING AXIALLY FROM THE DRUM, AND MEANS ENGAGING THE PROJECTING SHAFT FOR DRIVING THE 